Macro partitioning
Among overweight women, higher intake of trans, saturated, and animal fats is associated with greater long-term weight gain, whereas total fat percentage shows only a weak association.
If you are overweight, paying attention to the *type* of fat you eat matters more than the total amount. Specifically, increasing your intake of trans fats, saturated fats, and animal fats is associated with greater weight gain over time. You do not need to fear monounsaturated or polyunsaturated fats as much, as they were not associated with weight gain in this study. Focus on quality of fat sources rather than just total fat grams.
Among overweight women, for every one percentage increase in percentage of calories from trans fat, women gained an additional 2.3 lb (95% confidence interval, 1.80 to 2.86).
Why this rating
Large prospective cohort (N=41,518), long follow-up (8 years), adjusted for multiple confounders, though observational design limits causal inference.
Source
Dietary Fat and Weight Gain Among Women in the Nurses’ Health Study
Alison E. Field et al. · Obesity · 2007
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